Yeah, even Elon said they "can't rule it out". http://www.zerohedge.com/news/2016-09-11/elon-musk-we-have-n...

And I gotta say, it still seems more likely than helium exploding. Since helium is an inert gas.

But lots of peeps on here fail the great filter part of Fermi's Theory, so you can expect the downvotes anyway.